Method and apparatus for seam-welding steel pipes
US4341938A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1980 |
| Grant date | Jul 27, 1982 |
| Priority date | — |
| Expiry date | Dec 12, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K9/0253
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of longitudinally seam-welding steel pipes comprises the steps of providing a conductive net-like enclosure tube around a cable for supplying a direct electric current from the power source to the welding head; and conducting a direct electric current through the enclosure tube and through the steel pipe in a direction opposite to that in which the direct current runs through the cable. Apparatus for longitudinally seam-welding steel pipes comprises an electrical cable coupled to a welding head, a net tube surrounding the cable, and a device for supplying a direct electric current to the cable in a first direction and to the net enclosure tube and steel pipe in the opposite direction. The direct currents flowing in the enclosure tube and in the steel pipe is adjustably controlled to minimize the magnitude of a magnetic field created around the net enclosure tube and producing a welded steel pipe seam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.